Overlock sewing machine



FIG. 1 is a perspective view of an overlock sewing machine showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is another perspective view showing the overlock sewing machine. 

The ornamental design for an overlock sewing machine, as shown and described. 